15,058 research outputs found

    Moment Analysis and Zipf Law

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    The moment analysis method and nuclear Zipf's law of fragment size distributions are reviewed to study nuclear disassembly. In this report, we present a compilation of both theoretical and experimental studies on moment analysis and Zipf law performed so far. The relationship of both methods to a possible critical behavior or phase transition of nuclear disassembly is discussed. In addition, scaled factorial moments and intermittency are reviewed.Comment: Caption of Fig.6 was corrected. Review paper for WCI (World Consensus Initiative) Book "Dynamics and Thermodynamics with Nuclear Degrees of Freedom", published in Euorpean Physics Journal A as part of the Topical Volume. 16 pages, 21 figure

    Information entropy in fragmenting systems

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    The possibility of facing critical phenomena in nuclear fragmentation is a topic of great interest. Different observables have been proposed to identify such a behavior, in particular, some related to the use of information entropy as a possible signal of critical behavior. In this work we critically examine some of the most widespread used ones comparing its performance in bond percolation and in the analysis of fragmenting Lennard Jones Drops.Comment: 3 pages, 3 figure

    2-Amino­terephthalic acid–4,4â€Č-bipyridine (1/1)

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    The asymmetric unit of the title compound, C10H8N2·C8H7NO4, contains two half-mol­ecules, which constitute a 1:1 co-crystal. The 2-amino­terephthalic acid mol­ecule is situated on an inversion center being disordered between two orientations in a 1:1 ratio. In the 4,4â€Č-bipyridine mol­ecule, which is situated on a twofold rotational axis, the two pyridine rings form a dihedral angle of 37.5 (1)°. In the crystal, mol­ecules are held together via inter­molecular N—H⋯O and O—H⋯N hydrogen bonds. The crystal packing exhibits π–π inter­actions between the aromatic rings with a centroid–centroid distance of 3.722 (3) Å

    HyperINR: A Fast and Predictive Hypernetwork for Implicit Neural Representations via Knowledge Distillation

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    Implicit Neural Representations (INRs) have recently exhibited immense potential in the field of scientific visualization for both data generation and visualization tasks. However, these representations often consist of large multi-layer perceptrons (MLPs), necessitating millions of operations for a single forward pass, consequently hindering interactive visual exploration. While reducing the size of the MLPs and employing efficient parametric encoding schemes can alleviate this issue, it compromises generalizability for unseen parameters, rendering it unsuitable for tasks such as temporal super-resolution. In this paper, we introduce HyperINR, a novel hypernetwork architecture capable of directly predicting the weights for a compact INR. By harnessing an ensemble of multiresolution hash encoding units in unison, the resulting INR attains state-of-the-art inference performance (up to 100x higher inference bandwidth) and can support interactive photo-realistic volume visualization. Additionally, by incorporating knowledge distillation, exceptional data and visualization generation quality is achieved, making our method valuable for real-time parameter exploration. We validate the effectiveness of the HyperINR architecture through a comprehensive ablation study. We showcase the versatility of HyperINR across three distinct scientific domains: novel view synthesis, temporal super-resolution of volume data, and volume rendering with dynamic global shadows. By simultaneously achieving efficiency and generalizability, HyperINR paves the way for applying INR in a wider array of scientific visualization applications

    Photometric observations of selected, optically bright quasars for Space Interferometry Mission and other future celestial reference frames

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    Photometric observations of 235 extragalactic objects that are potential targets for the Space Interferometry Mission (SIM) are presented. Mean B, V, R, I magnitudes at the 5% level are obtained at 1 - 4 epochs between 2005 and 2007 using the 1-m telescopes at Cerro Tololo Inter-American Observatory and Naval Observatory Flagstaff Station. Of the 134 sources which have V magnitudes in the Veron & Veron-Cetty catalog a difference of over 1.0 mag is found for the observed-catalog magnitudes for about 36% of the common sources, and 10 sources show over 3 mag difference. Our first set of observations presented here form the basis of a long-term photometric variability study of the selected reference frame sources to assist in mission target selection and to support in general QSO multi-color photometric variability studies.Comment: 40 pages, 13 figures, 4 table

    Transverse Momentum Dependent Light-Cone Wave Function of B-Meson and Relation to the Momentum Integrated One

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    A direct generalization of the transverse momentum integrated(TMI) light-cone wave function to define a transverse momentum dependent(TMD) light-cone wave function will cause light-cone singularities and they spoil TMD factorization. We motivate a definition in which the light-cone singularities are regularized with non-light like Wilson lines. The defined TMD light-cone wave function has some interesting relations to the corresponding TMI one. When the transverse momentum is very large, the TMD light-cone wave function is determined perturbatively in term of the TMI one. In the impact bb-space with a small bb, the TMD light-cone wave function can be factorized in terms of the TMI one. In this letter we study these relations. By-products of our study are the renormalization evolution of the TMI light-cone wave function and the Collins-Soper equation of the TMD light-cone wave function, the later will be useful for resumming Sudakov logarithms.Comment: Minor change in text, 7 pages, two figure

    Preliminary results using a P300 brain-computer interface speller: a possible interaction effect between presentation paradigm and set of stimuli

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    Fernåndez-Rodríguez Á., Medina-Juliå M.T., Velasco-Álvarez F., Ron-Angevin R. (2019) Preliminary Results Using a P300 Brain-Computer Interface Speller: A Possible Interaction Effect Between Presentation Paradigm and Set of Stimuli. In: Rojas I., Joya G., Catala A. (eds) Advances in Computational Intelligence. IWANN 2019. Lecture Notes in Computer Science, vol 11506. Springer, ChamSeveral proposals to improve the performance controlling a P300-based BCI speller have been studied using the standard row-column presentation (RCP) par-adigm. However, this paradigm could not be suitable for those patients with lack of gaze control. To solve that, the rapid serial visual presentation (RSVP) para-digm, which presents the stimuli located in the same position, has been proposed in previous studies. Thus, the aim of the present work is to assess if a stimuli set of pictures that improves the performance in RCP, could also improve the per-formance in a RSVP paradigm. Six participants have controlled four conditions in a calibration task: letters in RCP, pictures in RCP, letters in RSVP and pictures in RSVP. The results showed that pictures in RCP obtained the best accuracy and information transfer rate. The improvement effect given by pictures was greater in the RCP paradigm than in RSVP. Therefore, the improvements reached under RCP may not be directly transferred to the RSVP.Universidad de Målaga. Campus de Excelencia Internacional Andalucía Tech

    Risk Factors Associated with Opioid Use Among African American Faith-Based Populations

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    African Americans (AAs) in the Midwest are more likely to die from an opioid overdose compared to Whites, despite lower rates of use. Little is known about factors related to opioid use among AAs residing in the Midwest, particularly church-affiliated AAs. AAs have the highest rate of church attendance among all racial/ethnic groups, and the Black Church may be an appropriate setting for prevention efforts. The present study sought to better understand factors related to opioid use among Midwestern church-affiliated AAs to inform future faith-based interventions. This study examined predictors of opioid use (ever) using survey data from Taking It to the Pews (TIPS), a faith-based HIV/STD/hepatitis C virus (HCV) education and testing intervention conducted in 4 AA churches (N = 250) in the Kansas City metropolitan area. Participants were predominantly female (71%) and church members (74%), with an average age of 47. Fifty-three percent of participants reported prescription opioid use at some point in their lifetime. Logistic regression analyses indicated that those who reported opioid use in their lifetime attended church more frequently, less likely to be on Medicaid, had a history of severe pain, a history of illicit drug use, and a history of marijuana use. AA churches are in a uniquely positioned to reach church congregants and community members utilizing church outreach services. AA churches may benefit from offering lifestyle interventions, such as exercise classes and stress management programs, for pain management and to prevent misuse of prescription opioids

    Construction of Lp\mathcal L^p-strong Feller Processes via Dirichlet Forms and Applications to Elliptic Diffusions

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    We provide a general construction scheme for Lp\mathcal L^p-strong Feller processes on locally compact separable metric spaces. Starting from a regular Dirichlet form and specified regularity assumptions, we construct an associated semigroup and resolvents of kernels having the Lp\mathcal L^p-strong Feller property. They allow us to construct a process which solves the corresponding martingale problem for all starting points from a known set, namely the set where the regularity assumptions hold. We apply this result to construct elliptic diffusions having locally Lipschitz matrix coefficients and singular drifts on general open sets with absorption at the boundary. In this application elliptic regularity results imply the desired regularity assumptions
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